Machine tools



Dec. 17, 1968 A. v. KLANCNIK MACHINE TOOLS Original Filed Sept. 29, 1964 i illo 5 Sheets-Sheet l .Adolph V. Klcmcnik MDM :Hi-farne@ Dec. 17, 1968 A. v. KLANCNIK MACHINE TOOLS 5 Sheets-Sheet 2 Original Filed Sept. 29, 1964 A. V. KLANCNIK MACHINE TOOLS Dec. 17, 1968 5 Sheets-Sheet 3 Original Filed Sept. 29, 1964 Inventor Jqolph U. Klaracn ora-Legs Dec. 17, 1968 A. v. KLANCNIK MACHINE TOOLS 5 Sheets-Sheet 4 Original Filed Sept. 29. 1964 lnvenor g'cfolph. V. Klancrzk` www Dec. 17, 1968 A. v. KLANCNIK MACHINE TOOLS 5 Sheets-Shed?, 5

original Filed sept. 29, 1964 vMM @www mvfwm .nK D... Aw

nited States Patent O 3,416,173 MACHINE TOOLS Adolph V. Klancnik, 1020 Glenview Road, Glenview, Ill. 60025 Original application Sept. 29, 1964, Ser. No. 400,126, now Patent No. 3,289,884, dated Dec. 6, 1966. Divided and this application Mar. 28, 1966, Ser. No. 537,866

8 Claims. (Cl. 10-107) ABSTRACT F THE DISCLOSURE An equalized clamping device for a workpiece in a machine tool comprises a pair of slideable blocks or jaws and means are afforded to assure that when the jaws are moved to grip the workpiece they do so by moving through equal increments at the same rate.

This invention relates generally to automatic machine tools, and in particular to those which incorporate a magazine for automatically feeding workpieces to a work station.

This application is a division of my application Ser. No. 400,126, tiled Sept. 29, 1964 and now Patent No. 3,289,884.

The present invention is concerned with an automatic machine tool for performing any one of a number of machining operations such as drilling, reaming, tapping, countersinking or the like on relatively small, generally cylindrical workpieces such as rivets, studs and spacers used in the assembly of mechanical components. Workpieces of this character may vary widely in overall configuration, and are generally produced at a fast rate and in great numbers. These considerations are for the most part a manifestation of industrial miniaturization.

In machine tools capable of handling small workpieces with cylindrically-shaped portions, particular difficulty has been experienced in accurately centering the small piece in its proper orientation, and accordingly an object of the invention is to clamp the workpiece accurately in centered position by affording a mechanism which moves a pair of clamping jaws simultaneously toward one another at the same rate so that the workpiece is centered between the clamping jaws.

With workpieces having a hollow cylindrical portion, a problem exists in holding the workpiece without damaging the thin side walls of the cylindrical member while maintaining the necessary holding or clamping pressure thereon during the entailed machining operation. Therefore, another object of the present invention is to provide an equalizing gripping means at the work station for gripping the hollow cylindrical articles while a clamping force is applied to the rear surface thereof to clamp the article during a machining operation.

A further object of the invention is lto feed a workpiece positively into position at a work station under circumstances where such positioning is accompanied by removal of machining chips from the work station.

In positioning workpieces in prior art devices, it is customary to engage one side of a workpiece and move the workpiece against a xed reference stop or surface. With such positioning, any variation in size of the workpiece between these sides thereof results in displacement of the point on the workpiece which should be engaged by a tool, such displacement being equal to the variation in size. Accordingly, a further object of the invention is a new and improved work holder capable of centering a workpiece between two movable members each engaging opposite sides of the workpiece to center the workpiece therebetween and thereby to halve any variation in size, if any, between the sides of the workpiece.

Another object of the invention is to clamp or hold various sizes and configurations of workpieces at a work station by selectively sized and configured clamping studs or elements securable to a piston rod of a uid operated cylinder thereby eliminating the need for adjustment of the stroke of a piston rod or of the location of the cylinder and piston.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show preferred embodiments of the present invention and the principles thereof and what is now considered to be the best mode contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention.

In the drawings:

FIG. 1 is a perspective view of the machine tool for automatically feeding a workpiece and holding the workpiece at a work station in accordance with the present invention;

FIG. 2 is a plan view of alternative right or left hand feed hoppers for the machine tool in accordance with the present invention;

FIG. 3 is a plan view showing the location of the fluid cylinders for operating the feeding and clamping mechanisms of the present invention;

FIG. 4 is a sectional and side view showing a workpiece in position at the work station;

FIG. 5 is a front view of the machine tool constructed in accordance with the preferred embodiment of the invention;

FIG. 6 is a plan view taken in section through the magazine;

FIG. 7 is a sectional view of another embodiment of clamping jaws and a back clamp stud in accordance with the present invention;

FIG. 8 is a schematic view of the mechanism; and

FIG. 9 is a perspective view of the support for the vibratory hopper.

Referring now to the drawings, and more particularly to FIG. 1, there is illustrated a machine tool 10 constructed in accordance with the preferred embodiment of the invention. The machine tool 10 includes a vibratory type of conventional hopper 11 in an elevated position and arranged to feed a plurality of workpieces WP downwardly over an arcuate and slotted guide chute 12 to a vertically oriented magazine 14 for the workpieces WP.

work clamping The workpieces WP are arranged in a vertical stack one upon another in the magazine 14, and in timed relationship the lowermost workpiece WP1 is fed at right angles outward from the bottom of the stack in the magazine 14 Iby a reciprocatory blade or pusher 15, and is positioned beneath a transfer pusher 18, which moves in a vertical path at one side of the magazine 14. The vertical pusher 18 operates in timed relationship to drive the workpiece WP1 downwardly into a work station WS. At the work station WS there is a front plate 20 having an aperture 21 to receive the tool 22 mounted on a spindle 23 of the machine 10.

During the machining operation, the spindle 23 moves rightwardly, FIG. 1, to insert the tool 22 through the opening 21 in the front plate 20 and into engagement with the workpiece WP at the work station WS. After the machining operation, the tool 22 is returned to the position shown in FIG. 1, and a new cycle is begun. Operation of the transfer pusher 18 to drive the next succeeding workpiece WP1 into position also causes the previously machined workpiece to be ejected downwardly from the work station WS and into a downwardly inclined trough 24.

An important aspect of the present machine tool is the ability to readily adjust the position of the magazine 14 and the position of the entire work station WS relative to the spindle 23. The high degree of flexibility in handling small workpieces and of ready and accurate alignment of these workpieces with the spindle and tool 22 results in less set-up time and lower cost of machining. The work station WS and the magazine 14 are supported on a main bolster or fixture plate 20, FIG. 4, which is adapted to be moved both vertically and horizontally relative to the spindle 23 and tool 22 on the machine frame. The magazine 14 is attached to the bolster plate 29 by an angle-shaped bracket 30, FIG. 4. More specifically, a downwardly extending leg 31 of the angleshaped bracket 30 is secured to a rear plate 32, FIG. 4, of the magazine 14 and a rearwardly extending leg 35 of the angle-shaped bracket 30 is secured to the top surface of the bolster 29 by a cap screw 48 threaded into the bolster 29. Thus, the magazine 14 is secured to the bolster 29 and its position relative to the tool 22 is adjusted with movement of the bolster plate 29.

The bolster plate 29 has its rear surface abutted against a plate 26 of a rectangular shaped box mount BM which is rigidly secured to the main frame of the machine tool. For the purpose of moving the bolster plate 29 in a horizontal direction relative to t-he main frame and box mount BM, a rearwardly extending block 27, FIGS. 6 and 8, is xedly secured to the bolster plate 29 and a pair of push-pull screws 31 and 33 extending at right angles to the block 27 are for pushing and pulling the bolster plate 29 relative to the box mount BM. In a familiar manner, the screw 31 is threaded in the block 27 and has its end engaging the box mount BM. Thus, the screw 31 may be turned to push the mounting plate leftwardly as viewed in FIG. 6. To pull the bolster plate 29 rightwartdly, the pull screw 33, extending Ithrough an opening in the block 27 and threaded in the bolster, is turned to pull the bolster 29 therewith.

For the purpose of moving the bolster plate 29 vertically relative to the box mount BM, push and pull screws 36 and 37, FIG. 1, are associated with a block 38 fastened to the upper surface of the bolster plate 29. The push screw 36 is threaded in the block 38 and has its end engaging the upper surface of the box mount BM so that with turning of the screw 36, the bolster plate may be forced vertically upward. To move the bolster plate 29 downwardly the pull screw 37 is turned further into the box mount BM in which it is threaded.

In addition to being able to move the bolster plate vertically and leftwardly and rightwardly as viewed in FIG. 1, it is also an attribute of the present invention that the bolster plate can be moved fore and aft relative to the spindle 23 and tool 22. As best seen in FIG. 9, the box mount BM is mounted on a slideway S formed on the main frame of the machine, and as seen in FIG. 8, a tightening screw 39 engaged in the groove within the slideway S serves to lock the box mount BM in its adjusted fore and aft position.

Often a change in size or conguration of the workpiece necessitates relative movement between the magazine 14 and the bolster plate 29. The magazine 14 is held in a locked position by cap screw 48, FIG. 4, extending through leg 35 of angle bracket 30 and threaded into the bolster plate at 50.

The cap screw 48 extends through an elongated s-lot 51, FIG. 6, formed in the angle bracket 30; and the cap screw 48 extends through an aperture in a plate 46, FIG. 6, overlying the leg 35 of the angle bracket 30. This plate 46 is secured to the bolster plate 29 by cap screws 49, FIG. 6.

For the purpose of pushing the magazine 14 leftwardly, FIG. 4, a screw 40, FIGS. 4 and 6, is threaded lll on a horizontal axis through the plate 41 with the end 0f the screw 4t) bearing against the rear vertical surface 44 of lhorizontal leg 35 or" angle bracket 30. Thus, turning of the screw 4G in the plate 41 forces the angle bracket 30 fleftwardly, FIG. 4, to move the attached leg 35 of bracket 30 leftwardly across the upper surface of the bolster plate 29. The angle bracket 30 is limited in this movement by the length of the elongated slot 51 therein through which extends the cap screw 48.

To pull the magazine 14 and bracket 30 rightwardly as viewed in FIG. 4, a pull screw 47 extends through an oversized opening in the plate 41 and is threaded at 45 in leg 35 of the bracket 3) so that by turning the screw 47 the leg 35 is pulled rightwardly relative to plates 41 and 46.

To locate the magazine 14 in a given position, the locking bolt 48 extending downwardly through openings in the plate 46 and leg 35 of the bracket 30 is tightened into its threaded opening 51) in the bolster 29, FIG. 4. The locking bolt 48 extends through the elongated slot or opening 51 in the leg 35 of the bracket 30 as already noted so that the bracket 30 `can be moved relative to the locking bolt 48 until the locking bolt 48 is tightened. Thus, after movement of bracket 3G and magazine 14 by turning one of the pushing or pulling screws 40 or 47, the locking pin 48 is tightened to clamp the magazine 14 in its adjusted position.

The magazine 14 has a pair of vertical guide plates or rails 60 and 61, FIGS. 1 and 5 horizontally spaced from one another to provide a guide channel 62 between their adjacent edges to receive the ,cylindrical shaft portion of a headed workpiece WP. The guide rails 60 and 61 are secured to the vertical plate 32 by a plurality of screw assemblies 64 having an outer screw and an inner socket cap screw. The guide rail 60 is adjustable so that the guide channel 62 can be varied in width to provide a complementary sized opening for the thickness of the workpiece being moved through the guide channel 62. To this end, the guide rail 60 is formed with elongated slots 65, FIG. 5, inclined upwardly at an oblique angle so that, after loosening the screws 64, the guide rail 60 can be shifted simultaneously vertically and horizontally. The guide rails 60 and 61 are moved fore and att relative to the back 4plate 32 by turning the outer screws which are threaded in side plates 60 and 61. The inner socket cap screws are threaded in the plate 32 and lock the outer screws and guide rails 6i) and 61 in position. Thus, the space can be adjusted for receiving different thicknesses as well as different diameters of Iheads of workpieces.

The guide plate 61 is shifted vertically upon loosening its respective screw assembly 64, FIG. 5, and elongated vertically oriented slots 66 formed therein allow the lower edge 67 of the slide 61 to be adjusted vertically to deine the width of a cross or horizontal guide channel 68, the

lower edge of the channel 68 being an upper edge 69 of a front guide plate 70.

The front plate 70, FIG. 5, is secured by cap screws 72 to the plate 32. The cap screws 72 are disposed within elongated, horizontal slots 73 formed in the plate 70 so that the guide plate 70 can be moved leftwardly or rightwardly along a horizontal path, FIG. 5, to vary the width of a vertical guide slot or channel 74 at the right hand end of the plate 70 as viewed in FIG. 5. The channel 74 is alforded by the right lhand end 75 of the plate 70 and an adjacent guide surface 76 of a vertically disposed spring biased pawl guide 78.

The pawl guide 78 is mounted for swinging movement on a horizontal pivot pin 79, and is biased by a leaf spring 80 in a clockwise direction, FIG. 5, about the pivot pin 79, to bring the upper right hand rear surface 83 of the pawl guide 78 into engagement with an eccentrically mounted stop element 84 for the pawl guide 78. The stop element is held iixed in an adjusted position by a screw 85, and it will be appreciated that by loosening screw 85 the eccentric 84 can be turned to so position the guide surface 76 of the pawl guide 78 to either increase or decrease the transfer guide slot 74.

The pawl guide 78 is secured by the pivot pin 79 to a support plate 34, FIGS. 1 and 5, extending vertically and in spaced relationship to the bolster plate 29. A spacing and mounting block 34A, FIG. 1, is interposed between the support plate 34 and the bolster 29. Elongated slots 34B in the support plate 34 receive the cap screws 34C which are threaded in the spacing block 34A which in turn is secured to the bolster thereby securing the support plate 34 and spacing block 34A to the bolster 29. When it is desired to change the width of the groove 74 between the pawl 78 and the vertical end 75 of the side plate 70 to accommodate a change in the diameter of the workpiece WP, the cap screws 34C are loosened and the support plate 34 is shifted horizontally within the limits afforded by the length of the slots 34B. The shifting of support plate serves as the rough adjustment for changing the size of the slot 74 and the turning of the eccentric 84 to pivot the pawl guide 78 serves as the ne adjustment for the slot 74.

As described hereinbefore, the workpieces WP move downwardly in the magazine 14 between the guide plates 60 and 61 to engage the top surface 69 of the guide plate 70, whereupon in timed relationship the pusher 15 moves rightwardly, FIG. 5, to move the lowest one of the stacked workpieces WP to engage a recessed edge 88, FIG. 5, of the pawl guide 78. After this occurs, a vertically operable transfer blade 9i), FIG. 5, moved by the slide 18, moves downwardly to force the workpiece WP downward in the guide slot 74 and into the mouth 92 at the work station between a pair of opposed clamping jaws 95 and 96.

Because of the recessed area 88 on the guide pawl 7S and the adjustment of the eccentrically mounted stop 84, the g-uide slot 74 has a dimension slightly under that of the workpiece to be moved therethrough so that as the workpiece is forced downwardly through the guide slot 74 by the transfer slide 90, the workpiece forces the pawl guide 78 to pivot in a counterclockwise direction. Thus, the spring biased pawl will assure that the workpiece WP will be guided by continuous engagement with the guide surface 75 of the guide channel 74 until the workpiece enters the mouth 92 of the clamping jaws or blocks 95 and 96.

The clamping jaws or blocks 95 and 96 are beveled at their upper edges at the mouth 92 and have tapering surfaces 97 and 98, FIG. 5, inclined toward each other for guiding the workpiece to suitably shaped clamping surfaces 99 and 100 by which the work-piece WP is gripped for a machining operation.

An important aspect of the present invention is the way in which the workpiece WP is held and centered prior to a final holding or clamping operation. Under the present invention the clamping jaws 95 and 96 are moved simultaneously toward one another to produce selfcentering of the workpiece and to exert holding or clamping forces on the sides of the cylindrical surfaces of the workpiece WP. Because the workpiece WP in many instances has a hollow and thin walled cylindrical portion, the side clamping pressure is relatively light as compared with the back clamping pressure afforded by a back-up support in the form of a stud 185, FIG. 4.

The clamping force for centering and clamping the workpiece by the jaws 95 `and 96 is generated by a fluid operating cylinder 110, FIGS. 5 and 8, which forces its piston 111 rightwardly, as viewed in FIGS. 5 -and 8, into engagement with a surface 112 of a plate 113. The plate 113 is secured to a slide block 115 disposed between the jaw 96 and the plate 113 so that movement of the plate 113 rightwardly by the piston 11 is accompanied by movement of the clamping jaw 96 rightwardly. In order to move the opposite clamping jaw 95 leftwardly at the same time as the clamping jaw 96, and at the same rate of movement so as to provide the self-centering movement of the clamping jaws 95 and 96, there is provided a selfcentering motion transfer mechanism which includes a 6 slideable bar 118, FIGS. 5 and 6, disposed to slide in spaced L-shaped brackets 119, FIG. 4, secured to the bolster 29 by cap screws 117.

The transfer bar 118 has its left hand end 120, FIGS. 5 and 8, in engagement with the plate 113, and has its right hand end 121, FIG. 6, in engagement with a stop member 122. The stop member 122 is threaded in a motion transfer lever 124 which is pivoted on a pin 125, FIG. 6, of a block 126 xed to the bolster plate 29. The motion transfer lever 124 has at its forward end an adjustable screw 129, which has a lock nut 130 to secure the screw 129 in a given rotative position. The end 131 of the screw 129 is in engagement with an actuating plate 132 which is secured by screws (not shown) to a slide block 135, FIGS. 6 and 8. The slide block 135 has the clamping jaw secured thereto by fasteners 144, FIGS. l `and 7. The manner of supporting the slide Iblocks and 135, which carry the respective clamping jaws 95 and 96, is best explained in yconjunction with FIGS 5, 7 and 8. As seen in FIGS. 5 and 7, spaced guiding blocks 138 and 139 respectively extend from the rear surface of the front plate 20 to bolster plate 29 and are secured by fasteners 140, FIG. 5, to the Ibolster plate 29. The blocks 138 and 139 have la rectangular groove 143, FIG. 7, therein, at the front portions thereof in which slide the slide blocks 115 and 135. As best seen in FIGS. 4 and 5, the slide block 96 slides on the lower guiding surface 1438 of the groove 143.

The clamping jaws 95 and 96 `are clamped to their respective slide blocks and 115 by `cap screws 144, FIG. 5, so as to move directly with these slide blocks in response `to operation of the uid operable cylinder 110.

Recapitulating, operation of the fluid cylinder 110 moves the pist-on 111 rightwardly into engagement with the surface 112 of the plate 113. The piston 111 is able to force the plate 113 in its attached slide block 115 rightwardly to begin to move the clamping jaw 96 secured thereto by cap screws 144 towards a `center line CL, FIG. 5, for the workpiece WP. The lower portion of the plate 113 is in engagement with the leftward end 120 of the transfer bar 118, and the transfer bar 118 moves with the plate 113, slide block 115, and clamping jaw 96.

The right end 121, FIG. 6, of the transfer bar 118 pivots the motion transfer lever 124 to swing its forward portion containing the screw 129 leftwardly to bear against the plate 132. This forces the plate 132 and attached slide block 135 leftwardly to push the clamping block 95 toward the clamping block 96.

The length of the lever 124 is such that the screw 129 moves the same proportionate distance as the screw 122 at the rearward end of the lever 124. Stated differently, the lever 124 is adapted to provide a one-for-one transfer of motion from one direction to an equal amount of motion in the opposite direction. Thus, it will be apparent that the clamps 95 and 96 are rnoving toward each other with the same rate of movement and moving through the same distance to center therebetween the workpiece on the center line CL.

The slide blocks 135 and 115 are spring biased to hold the jaws 95 and 96 in their clamping positions, as will be explained in detail hereinafter. Therefore, when the succeeding workpiece WP1 is pushed into the slot between the incline planes 97 and 98 on the clamping jaws 95 and 96, the clamping jaws 95 and 96 move against the bias for sufficient spread at the lower edges 145, FIG. 5, of the arcuate clamping surfaces 99 and 100 to release the workpiece WP to drop into the eject chute 24, FIG. l. The lower edges of the clamping surfaces 99 and 100 define an opening which is of wider dimensions than the entrance into the arcuate surfaces 99 and 100. That is to say, the space between the inclined surfaces 97 and 98 at the arcuate clamping portions 99 and 100 is of a smaller dimension than the spacing between the lower edges 145 immediately therebelow. Preferably, the spacing between the inclined surfaces 97 and 98 leading to the arcuate clamping portions 99 and 100 is such that the lowermost workpiece WP is dropped or released when the head portion of the upper workpiece WP1 is 1/'32 of an inch from the head portion of the lower workpiece WP. Thus, the head portions of the workpieces WP and WPI do not come into Contact which might cause the canting of the workpieces WP and WF1 between the jaws 95 and 96.

The movement of the slide blocks 115 and 135 toward one another is limited by engagement of a stop screw 161, FIG. 5, with the left side surface 162 of the front plate and by ,engagement of screw 133 with the right side surface of thp front plate 20. The slide blocks 115 and 135 are biased toward one another to engage their respective stops 161 and 133 with the side edges of the front plate 20 by compression springs 150 and 150', FIG. 5, mounted on studs 152 and 152. The studs 152 and 152 are threaded into the left and iight sides of the front plate 20, respectively, and extend through apertures in the respective plates 112 and 132. The outer portions of the apertures in the plates 112 and 132 are enlarged to afford a spring seat for the respective compression springs 150 and 150' which are compressed between the seats and heads of the respective studs 150 and 150. Since the studs 150 and 150 are threaded into a non-movable front plate 20, their respective compression springs 150 and 150' act .against the seats of the respective plates 112 and 132 to force the plates 112 and 132 toward one another and thereby in -turn urge the slide blocks 115 and 135 toward one another to clamp under spring pressure a workpiece between the jaws 95 and 96.

The motion transfer lever 124 is urged to rotate to contact the end 121 of the transfer bar 118 by a compression spring 155 disposed within the housing 126, FIG. 6.

In the hereinbefore described operation of the clamping jaws 95 and 96, the clamping jaws and slide blocks were disposed so that the holding surfaces 99 and 100 were disposed equidistantly from the center line CL in both the biased clamping position and in the positive holding position under the cylinder pressure 110. However, there may be occasions when it is desired to machine workpieces in an off-center location, and the present invention is readily adapted to permit the off-center locating of the workpiece. For example, it may be desired to drill a hole in the cylindrical portion of the workpiece offset from the center or axis of the cylinder. This is accomplished by adjusting one of slides 135 or 115 and its associated clamping jaw 95 and 96 in a position to the right or left of the position shown and described hereinbefore. That is to say, if one of the clamping jaws 95 or 96 is moved to a position closer to the center line CL than the other clamping jaw 95 or 96, `then the equidistant movements of both clamping jaws results in the clamping jaws being offset to the center line CL.

For this purpose, the clamping jaw 96 can be moved relative to its centered position by turning stop screw 133, which bears against the left side of the front plate 20. Turning of screw 133 causes the slide block 135 to move relative to the front plate 20 either rightwardly or leftwardly. The adjusting screw 129 on the lever 124 should also be adjusted to be just contacting the plate 132 after having adjusted the spacing between the plate 132 and slide block 135. Similarly, the spacing or relative positions between the plate 113 and the slide block can be adjusted by turning stop screw 161 which bears against the right side of front plate 20.

The movement of the clamping jaws 95 and 96 through a predetermined distance results in operation of the back clamp 105. Thus, theback clamp 105 will not be effective if the clamping jaws 95 and 96 are prevented from moving to the clamping position, as for instance by the misalignment of a workpiece coming into the clamping jaws 95 and 96. Thus, the chance of damage to the work station by the back clamp 106 engaging a rnisaligned workpiece is lessened. The back clamp cylinder 108 is under the control of a microswitch 172, FIGS. 1 and 8, having an arm 173 extending into engagement with an actuating button on the transfer bar 118. When the transfer bar 118 moves rightwardly, FIG. 8, to bring the clamping jaws and 96 together, this movement is sensed by the arm 173 which is actuated to close the microswitch 172 which conditions the back clamp for operation. Thus, closing of microswitch 172 causes the cylinder 108 to move its clamping piston rod 106 forwardly, as viewed in FIG, 4, to bring the stud against the rear surface of the head H or" a workpiece and thereby clamp the head H against the rear surface 109 of the jaws 95 and 96. The back clamp piston rod 106 actuates a microswitch 174, FIG. 8, during its forward stroke to start the spindle cycle to bring the cutting tool 22 into engagement with the end E of the workpiece WPI. More specifically, a sensing lever extends through an opening in the bolster plate to engage the end of a lever 171 which is pivoted to close the microswitch 174 with the forward movement of the back clamp 106.

Preferably, the amount of clamping force afforded by the back clamp stud 105 is approximately seven times the force afforded by the side clamps 95 and 96. As best seen in FIG. 4, the stud 105 is fastened by set screw 175 to the piston rod 106 so that after loosening the set screw 175 the stud 105 can be removed to enable a stud of different proportions to be substituted, thereby adapting the machine for workpieces of different thickness and/or head size. In this manner, the present invention is particularly adapted to provide large flexibility in holding the workpiece from the rear by affording a change in studs as 105 rather than by a cumbersome adjustment of the piston stroke of the tluid cylinder 10S.

After the machining operation on the workpiece WPI, the spindle moves away from the work station WS and workpiece WP and pulses the cylinder 110 to retract the piston 111 for the clamping jaws 95 and 96 and pulses the cylinder 108 to retract the back clamp stud 105 away from the head H of the workpiece WP. The machine then commences a new operational cycle for the next workpiece WPI by pulsing the slidetransfer cylinder 176, FIG. 5, which actuates the horizontal cross slide 15 to force the workpiece WPI from the bottom of the stack and to move the workpiece WPI across the horizontal guide surfaces 67 and 69 to a position beneath the vertical transfer slide 90.

The cylinder 176, FIG. 5, is secured to the reverse side of a mounting plate 177, which has therein an opening in which is reciprocated a slide block 181 on which is secured the horizontal transfer slide 15. The slide block 181 reciprocates in the opening 180 and is attached by a clamping bolt 182, FIG. 6, to the piston 183 for the cylinder 176. Thus, as the piston rod 183 moves rightwardly, as viewed in FIG. 6, the slide block 181 moves in the opening 180 and inserts the transfer Slide pusher 15 through the guideway 68 to move the workpiece WPI rightwardly to a position against the recessed area 88 of the guide pawl 78.

As viewed in FIG. 6, the rightward movement of the piston 183 is limited by the engagement of the leading edge 185 of the piston engaging a stop screw 186 secured to the bolster plate 29 of the machine. The stop screw 186 is adjustable so as to render the amount of movement of the piston 183 variable, depending upon the size of the workpiece WP.

With the workpiece WPI, FIG. 5, against the guide pawl 78, the actuating cylinder 187, FIG. 4, for the vertical pusher 90 is actuated to drive the vertical pusher 90 downwardly to force the workpiece WPI through the guide slot 7d into the mount 92 leading to the work station WS` The actuating cylinder 187 for the vertical pusher 90 is secured by a number of cap screws 188 to the main vertical magazine back plate 32. The cylinder 9 187 drives a piston rod 190 which is attached by a bolt and nut fastener 191 to the slide block 18.

As best seen in FIG. 5, the upper portion of the vertical pusher 90 is secured by fasteners 192 flat against the side of the pusher block 18 to reciprocate therewith. The slide block 18 slides in an open vertical slot 194, FIGS. l and 5, dened between an edge 195 of a plate 193 and an edge 196 of an outer guide bar 197. As best seen in FIG. 6, the slide 18 is disposed to extend rearwardly of the blade 90 to ride against the forward surface 199 of the outer guide bar 197. Thus, the guide bar 90 is guided and held for reciprocating movement in response to actuation of the cylinder 187.

The piston rod 190 for the cylinder 187 moves downwardly until its leading edge 201 engages the top of a stop screw 202, FIG. 4, secured in the arm 35 of the bracket 30. The stop screw 202 is threaded for adjustment and can be locked in any one of a number of positions to limit the downwand movement of the piston 190. As seen in FIG. 4, the vertical blade 90 has a forward portion 210 disposed immediately above the workpiece WP1 and has a recess 211 in which is adapted to receive the head H of the workpiece WP1.

The Vertical blade 90 also has a leading nger 212 which is adapted to move downwardly behind the movable jaws 96 and 97 to clear out chips left from previous drilling or tapping machining operations. Thus, the vertical bla-de 90 performs the dual functions of removing chips from the clamping jaws 95 and 96 by the linger 212, and transferring a workpiece such as WP1 into the work station between the jaws 95 and 96.

In the embodiment of the invention shown in FIG. 7, back clamp stud 105A on piston rod 106A has an elongated slot 220 extending vertically through said stud and extending rearward from its forward edge 221. The slot 220 permits the finger 212 of the vertical plate 90 to be moved downwardly therethrough. Thus, the leading linger 212 is adapted to move through the stud 105A and' remove any chips from the recess 222 between the respective clamping jaws 95A and 96A. The clamping jaws 95A and 96A have recessed cut-outs 222 to permit the stud 105A to move forwardly to engage the head of the workpiece (not shown) which head will be in `a seat 230.

The clamping jaws 95A and 96A are similar to the clamping jaws 95 and 96 except that jaws 95A and 96A have been recessed at 222 to provide for a much shorter workpiece, which would have a very small shank of approximately the length afforded by arcuate side walls 99A and 100A. Thus, clamping jaws 95 and 96 or 95A and 96A or other suitable clamping jaws having lditferent congurations for the clamping surfaces 99 and 100 can be afforded for a large variety of shapes of workpieces which can be employed in the present machine tool. Furthermore, the clamping walls 99 and 100 need not be arcuate but may be of a general V-shape configuration to take various sizes and configurations of workpieces. To change the clamping blocks, it is merely necessary to remove the front plate 20 and loosen the cap screws 144 which hold the respective clamping jaws 96 and 95 on their sliding block 115 and 135.

To facilitate aligning of the discharge of the curved guide means 12 and the inlet to the magazine 14, the vibratory hopper 11 is mounted on a movable platform 295, FIG. 9, which is adapted to slide in a fore and aft direction toward the spindle 23 and tool 22. The movable platform 295 is supported on a generally vertical stand 296 having a lower roller portion 297 guided for rolling engagement along with guide rail 298. A handle 299 may be provided to tighten the clamp (not shown) on a clamping rail 300. With the guide means 12 properly aligned over the magazine 14 t-he handle 299 is turned to tighten the clamp on the rail 300 to lock the stand 296 and platform 295 in position.

The following brief description of operation is intended to facilitate understanding of the present invention. As viewed in FIG. 1, the workpieces WP are disposed in the vibratory hopper 11 where the workpieces are re-oriented from random positions to a position with the cylindrical shank portions extending downwardly through the slot 237 between the curved guilde plates 239 and 240. The outlet end of slot 237 of guide mea-ns 12 is aligned immediately above the guide slot 62, FIG. 5, and with the plates 60 and 61 of the vertical workpiece magazine 14. The bottom-most workpiece of the stack WPI in the magazine is transferred by pusher blade 15 in a horizontal direction beneath the vertical pusher or blade 90.

To operate the transfer -or horizontal blade 15, the horizontal transfer actuating fluid cylinder 176 is actuated by fluid under pressure to drive its piston 183 and attached slide block 181, which in turn is attached to the transfer pusher 15, rightwardly as viewed in FIGS. 1, 5 and 6. The piston 183 moves rightwardly until it engages the stop 186, FIG. 6, at which time the workpiece WPl will be disposed against the recess area 88, FIG. 5, of the guide pawl 78.

In timed relationship, the vertical cylinder 187 is actuated to ldrive its piston rod 190 downwardly. Piston 190 is attached to slide block 18 carrying the vertical blade 90, which moves downwardly into driving engagement with workpiece WP1. The nger 212, FIG. 4, of the pusher precedes the entry of the workpiece through the opening in the button to wipe and to force downwardly any accumulated chips. The vertical blade 90 moves the workpiece WP1 downwardly and the edge 76 of the pawl guide 78 urges the workpiece WF1 against the side 75 of the guide channel during the downwar-d movement of the workpiece WPI into the mouth 92 between the gripping jaws 95 and 96.

T-he guiding surfaces 97 and 98, respectively, of the jaws 95 and 96, are inclined toward one another in a convergent manner towards their respective gripping surfaces 99 and 100. Thus, as the vertical blade 90 forces the workpiece WP1 further into the gripping jaws 95 and 96, the jaws 95 and 96 are forced to spread apart and the previous workpiece WP drops from the lower portion of the jaws 95 and 96 into an eject chute 24 leading to the collecting stations for the finished workpieces.

With the new workpiece disposed at the work station WS between the clamping surfaces 99 and 100 of jaws 95 and 96 which are biased toward each other by compression springs 150, a positive side clamping operation is initiated by actuation of the clamping cylinder 110. As seen in FIG. 8, the cylinder drives its piston 111 rightwardly to engage the surface 112 of a plate 113 connected to the slide block 115 carrying the left clamping jaw 96.

The plate 113 against which the piston 111 is engaged also bears against the leftward end of a horizontally disposed transfer bar 118 which has its Iopposite end 121, FIG. 6, disposed against a rearward end of a one-for-one motion transfer lever 124. The forward end of the motion transfer lever 124 has an actuating screw 129 with its tip 131 bearing against a pusher plate 132 on which is secured the right-hand clamping jaw 95. Thus, as the left-hand clamping jaw 96 moves, there is an accompanying equal movement of the right-hand clamping jaw 95 so that the workpiece WPI is being centered as it is being clamped by the jaws 95 and 96. The clamping pressure afforded by the clamping jaws 95 and 96 is limited to a predetermined extent so that the clamping pressure will not damage any hollow or thin walled cylindrical members due to excessive side clamping pressures.

Rightward movement of the transfer rod 118, FIG. 8, actuates rod 173 to close microswitch 172 to begin a back clam-ping operation by the stud 105. Microswitch 172. causes actuation of the cylinder 108 to move its piston rod 106 leftwardly as viewed in FIG. 4, to bring stud 105 against the rear surface of the head H of the workpiece WP. The stud 105 forces the head H against the rear surfaces 109 of the respective clamping jaws 95 and 96 and exerts sufficient pressure thereon to hold the workpiece. The back clamp stud 105 rotates a lever to actuate a rod 170 to close microswitch 174 to initiate the moving of the spindle and insertion of the tool 22 through the opening in the front plate to perform the machining operation.

After the machining operation, the spindle 23 returns the tool 22 from the opening 21 in the front plate 20, and the operation of the transfer cylinder 176 is initiated to begin the next feeding and machining cycle of operation.

With long-shank workpieces, as illustrated in the drawings, the hopper 11 is a counterclockwise hopper for shank-heavy workpieces, FIG. 2, whereas an alternate hopper 11A, as shown in FIG. 2, as being a clockwise hopper, could feed head-heavy elements to the magazine 14; reference to counterclockwise and clockwise being in the sense of the direction of movement of the workpieces in the hopper. The hoppers are carried on a slideable carriage such as shown in FG. 9 so that merely by moving the carriage relative to the magazine 14, a clockwise or counterclockwise hopper can be aligned in a ready manner with the magazine 14.

The size of the transverse guide slot 63 is readily changed by moving the guide plate 61 vertically along the elongated slots 66 and then tightening the cap screw 64. The guide slot 74 through which reciprocates the vertical pusher 90 is adjusted by loosening the cap screws for the plate 70 and moving it rightwardly of leftwardly along its elongated slots 73 and/ or by turning the eccentric 84 so as to move the pawl guide 78 clockwise or counterclockwise. The pawl guide '78 is locked in position by tightening cap screw for the eccentric 84.

The amount of movement of the clamping jaws 95 and 96 toward one another and thereby the spacing between the arcuate holding surfaces 99 and 100 on the clamping jaws 95 and 96 can be varied by turning the adjusting screws 161 and 133, which determine the relationship between the respective slide block 115 and 135 and their respective pushing plates 113 and 132 to prevent crushing of parts and clamping of tools on their walled parts.

1f it is desired to have the centering operation performed -on a non-symmetrical basis (that is, the workpiece is oriented and clamped and held so as to be machined not in the center of the workpiece but on an axis displaced either rightwardly or leftwardly from the center of the workpiece) the screw 129 is turned to move the plate 132 and sliding clamping jaw 95 either to the left or to the right. Thus, with the continued equal movements Iof the plate 132 and 113, the centering of the jaws 95 and 96 will find the jaw 95 displaced either rightwardly or leftwardly of the position it would assume if it had not been adjusted by the screw 129.

To accommodate the different size heads H or lack of a head on different workpieces, the present invention employs a replaceable stud 105 which is secured by a set screw 175 to the clamping piston rod 106. By changing the size and shape of the stud, the back clamping pressure and stroke can be maintained for changes in length of workpiece or thickness of head without changing the stroke of the cylinder 106, which would be a more cumbersome operation.

If necessary, the clamping jaws and 96 can be changed to give a different configuration of holding surfaces 99 and 100 for shapes of workpieces not suited to being clamped by the generally semi-circular holding surfaces 99 and 100. The clamping jaws 95 and 96 are replaced by loosening cap screws 144 for the respective slide blocks and 135 and attaching new clamping jaws to the respective slide blocks. Moreover, the clamping surfaces 99 and 100 need not be arcuate and, in some instances, V-shaped configurations are employed to accom.

modate a number of varying sizes of diameters of workpieces. Manifestly for workpieces of non-cylindrical or of unusual shapes the clamping surfaces 99 and 100 can be changed accordingly to accommodate the particular shape of the workpiece.

In addition to the foregoing adjustments, the entire magazine 14 can be moved forwardly or rearwardly by adjusting the push-pull screws 40 and 47, FIG. 6. The entire bolsterplate 29 is movable in three directions by push and pull screws to readily align the workpiece with the spindle 23 and tool 22.

From the foregoing it will be seen that the present invention is highly flexible in adjustment to accommodate various sizes and shapes of Small machine elements. Also, the present invention employs a centering device for moving the workpiece to a centered position by side clamps.

The side clamping pressure is 4adjustable to be less compared to the back clamping pressure affored by a button 105. By changing the size and the shape of the stud 105, the piston stroke 106 can be kept constant while changes due to thickness of the head or the size of the head can be accommodated by the changing of the button 105.

Hence, while I have illustrated and described preferred embodiments of my invention, it is to be understood that they are capable of variation and modification.

I claim:

1. A work holding and clamping device for clamping a workpiece at a work station of a machine tool with respect to 'a predetermined plane comprising: a first reciprocatory side clamp having a clamping surface thereon reciprocal along `a path in a first direction to engage its clamping surface with a workpiece at said work station, means to move the first clamp toward center position for clamping the workpiece, a second reciprocatory side clamp having a clamping surface engageable with the workpiece and being spaced from said first side clamp, said second reciprocatory side cla-mp being reciprocable along said path and toward said first reciprocatory side clamp to engage the workpiece between said surfaces and to locate said workpiece with respect to said predetermined plane at said` work station, actuating means for moving said second reciprocatory side clamp substantially simultaneously with the first, the last named means including a transfer slide engaged by said first clamp, a pivoted lever having two lever portions with one portion engaged by the slide and the other portion engageable with the second side clamp whereby movement of the slide pivots the lever and the lever moves the second clamp toward center position, through a distance and at a rate substantially equal to that of the first clamp, and resilient means normaly. effective to bias the side clamps toward one another.

2. A device according to claim 1 wherein at least one of the clamps is adjustable as to its normal position whereby the workpiece may be located on one side or the other of said plane.

3. A device according to claim 1 wherein said first and second`clamps have upper spaced guiding surfaces converging toward said clamping surfaces, and wherein said first and second clamps have a lower opening therebetween, the lower opening between said first and second clamps being larger than the smallest separation between the converging guiding surfaces so that forcing of a workpiece along said upper guiding surfaces forces said clamps apart against the urging of said biasing means to allow the workpiece held therebetween to drop therefrom.

4. A device according to claim 1, including a rear clamping means reciprocal at right angles to said reciprocatory path for said first and second clamps and adapted to engage a clamped workpiece at the rear surface thereof to provide a rear clamping force to said workpiece.

5. A device according to claim 4, wherein means are effective to sense movement of the clamping surfaces toward one another and thereupon condition the rear clamping means for actuation, and wherein means are effective to sense actuation of the rear clamp.

6. A device according to claim l, including means for forcing said workpiece from Said work sta-tion including an extension adapted to be reciprocated past said clamps to clear chips therefrom prior to the clamping of said workpiece.

7. In a machine toolof the character described, an equalized clamping device for clamping a generally cylindrical portion of a workpiece at a center postion, comprising: a frame, a first slideable block adapted to be recipe rocated along said -frarr'ie toward and away from said center position, a second slideable block adapted to be reciprocated along said frame toward and away from said center position, `a clamping surface on said first slideable block to receive said cylindrical workpiece, a clamping surface on said second slideable block to receive said cylindrical workpiece, power means adapted to en-gage said first slideable block and to reciprocate sand first slideable block -toward the center position for said workpiece, a transfer slide engaged by said first slideable block, and slideable along said frame with said first slideable block, a lever fmeans pivoted on said frame, said lever means having a first portion engaged by said transfer slide to pivot said lever as said transfer slide moves with said first slideable block, a second portion on said lever adapted to engage said second slideable block and to force said second slideable block toward said center position, said first and second portions of said lever being of equal length to provide an equal movement of said iirst and second slideablerblocks toward each other, and biasing means adapted to bias said first and second slideable blocks toward each other. i'

8. A machine Ytool according to claim 7 wherein ca bias means is eiective normally to bias said blocks toward one another, said blocks having upper sloped surfaces spaced from one another and converging towardI said clamping means, said clamping surfaces being separated at the bottom by a distance -greater than the smallest separation between said sloped surfaces. Y

References Cited UNITED STATES PATENTS 2,032,535 'rs/1936 Geist 1o1o1 2,518,086 8/1950 snorek 10g-107 XR 2,811,876 11/1957 Barcheider 1o- 101m LEoNrDAs vLAcHos, Primary Examiner. l

Us. c1. X.R. 269-34 

